Ranging method, device, and system

Abstract

To implement reliable ranging, a ranging method, an apparatus, and a system are disclosed. A first node measures a first ranging frame to obtain first measurement information (S202), and the first node transmits second measurement information based on the first measurement information and a first feedback scheme (S203). In other words, the manner in which the first node feeds back the measurement information needs to be determined based on the measurement result of the first node and the first feedback scheme. The ranging method implements feedback of measurement information within a ranging scenario, improving the reliability and flexibility of ranging.

Description

[Technical Field]

[0001] The present application relates to the field of communications technology, and in particular to ranging methods, devices, and systems. [Background technology]

[0002] With the continuous development of global communication technology, wireless communication technology is surpassing wired communication technology in development speed and applications, presenting a booming development trend. Smart devices such as smart transportation devices, smart home devices, and robots are gradually becoming part of people's daily lives. Based on wireless communication technology, devices can perform target positioning, ranging, angle measurement, detection, etc. For example, passive entry passive start (PEPS) is an example of an in-vehicle wireless positioning application. Users can automatically lock or unlock their vehicle doors by using an in-vehicle positioning system instead of a key to perform ranging on the vehicle key or mobile phone carried by the user.

[0003] Therefore, how to implement reliable ranging is an urgent technical problem to be solved. Summary of the Invention [Means for solving the problem]

[0004] The present application provides a ranging method, apparatus, and system for implementing reliable ranging.

[0005] According to a first aspect, a ranging method is provided, including: a first node receiving a first ranging frame on at least one channel; the first node measuring the first ranging frame to obtain first measurement information; and the first node transmitting second measurement information based on the first measurement information and a first feedback scheme.

[0006] In the embodiment of the present application, after the first node acquires the first ranging frame through measurement to obtain the first measurement information, the first node transmits the second measurement information based on the first measurement information and the first feedback method. In other words, the specific form in which the first node feedbacks the measurement information needs to be determined based on the measurement result of the first node and the first feedback method. This solution implements the feedback of measurement information in ranging scenarios and improves the reliability and flexibility of ranging.

[0007] The first feedback scheme may belong to a predefined or configured feedback scheme set, which defines multiple different feedback schemes, and in this solution, compared to a single fixed feedback scheme, this feedback scheme can improve the reliability of ranging while implementing flexible feedback of measurement information.

[0008] In one possible design, the first ranging frame includes at least one symbol, and the first measurement information indicates channel state information of at least one valid subcarrier corresponding to the at least one symbol (also referred to as a ranging symbol), e.g., the symbol is an OFDM symbol.

[0009] In this way, signal measurements are performed using symbols as granularity to improve the reliability of ranging.

[0010] In the embodiment of the present application, there are several possibilities for the first feedback scheme. The following are some examples of the possibilities:

[0011] 1. The first feedback scheme refers to the feedback of channel state information for all valid subcarriers.

[0012] In this case, the second measurement information and the first measurement information indicate the same channel state information.

[0013] Feedback method 1 may feed back detailed channel state information and may be used to improve the accuracy of ranging frames.

[0014] 2. The first feedback method refers to feedback of channel state information of the DC subcarrier, and the second measurement information includes channel state information of the DC subcarrier corresponding to at least one symbol, and the channel state information of the DC subcarrier is determined by performing interpolation based on the channel state information of valid subcarriers adjacent to the DC subcarrier.

[0015] The interpolation includes, but is not limited to, at least one of linear interpolation, nearest neighbor interpolation, cubic spline interpolation, and / or quadratic interpolation.

[0016] Feedback method 2 may be used to reduce the amount of feedback data, provided that the reliability of ranging is ensured.

[0017] 3. The first feedback method indicates feedback of channel state information of at least one subcarrier group, where at least one valid subcarrier corresponding to at least one symbol belongs to at least one subcarrier group, and the second measurement information includes channel state information of each subcarrier group in the at least one subcarrier group.

[0018] Below we list some possible grouping schemes:

[0019] In a possible design, there is one subcarrier group for every M consecutive subcarriers corresponding to at least one symbol, where M is a positive integer. In this way, the grouping intervals (i.e., the number of subcarriers included in a subcarrier group) of all subcarrier groups can be matched.

[0020] In a possible design, there is one subcarrier group for every P or L consecutive subcarriers corresponding to at least one symbol, where P and L are positive integers and P ≠ L. It may be understood that P and L coexist. In other words, two different grouping intervals may coexist. This can avoid the case where some subcarriers cannot be grouped when grouping is performed only in a single grouping interval (e.g., P), and can ensure that all subcarriers have a corresponding subcarrier group.

[0021] In a possible design, the at least one channel includes a first channel and a second channel, where there is one subcarrier group for every Q consecutive subcarriers in the subcarriers corresponding to the first channel, and there is one subcarrier group for every N consecutive subcarriers in the subcarriers corresponding to the second channel, where Q and N are positive integers and Q ≠ N. This can implement grouping with different grouping intervals on different channels, implement uneven grouping effects, and meet different requirements for CSI feedback accuracy of different channels.

[0022] Of course, in practical applications, uniform grouping may also be implemented, i.e. different channels correspond to the same grouping interval.

[0023] Feedback method 3 may be used to reduce the amount of feedback data, provided that the reliability of ranging is guaranteed.

[0024] In a possible design, the channel state information for each subcarrier group may be the average, median, maximum, or minimum of the channel state information of all valid subcarriers in the subcarrier group.

[0025] In this way, only one piece of channel state information needs to be fed back per subcarrier group to reduce the amount of feedback.

[0026] In a possible design, the channel state information of each subcarrier group may be the channel state information of one subcarrier in the subcarrier group, for example, the channel state information of the first subcarrier, the last subcarrier, or the middle subcarrier.

[0027] This can reduce the amount of feedback, have a simple implementation, be easy to implement, and have high reliability.

[0028] In a possible design, the number of subcarriers included in a subcarrier group is related to the ranging range. For example, a larger ranging range indicates a smaller number of subcarriers included in the subcarrier group, or a smaller ranging range indicates a larger number of subcarriers included in the subcarrier group.

[0029] In another possible design, the number of subcarriers included in the subcarrier group is related to the amount of data that can be fed back by the first node, for example, a larger amount of data that can be fed back by the first node indicates a smaller number of subcarriers included in the subcarrier group, or a smaller amount of data that can be fed back by the first node indicates a larger amount of subcarriers included in the subcarrier group.

[0030] In an embodiment of the present application, the first node may start measuring from a specified position in the first ranging frame. The following describes some possible measurement designs.

[0031] In a possible design, a symbol in the first ranging frame has a CP, and the first node measuring the first ranging frame includes the first node performing measurements starting from a first symbol in the first ranging frame.

[0032] In a possible design, the symbols in the first ranging frame do not have a CP, and the first node measuring the first ranging frame includes the first node performing measurements starting from a second symbol in the first ranging frame.

[0033] In this case, it can be understood that the first ranging frame does not have a CP to resist multipath interference, so the first symbol can be sacrificed to resist multipath interference and play the role of a CP, which improves measurement accuracy.

[0034] In a possible design, the first node performs measurements starting from a specified symbol in the first ranging frame based on instructional information or a preset configuration.

[0035] Of course, the above three design approaches are merely examples and are not limiting.

[0036] In a possible design, the first ranging frame includes a plurality of symbols, and the first node measuring the first ranging frame includes: the first node determining, based on channel state information corresponding to the plurality of symbols, channel state information corresponding to an Rth symbol in the first ranging frame, where R is a positive integer, and the first measurement information indicating the channel state information corresponding to the Rth symbol; or the first node determining, based on the channel state information corresponding to the plurality of symbols, an average value of the channel state information corresponding to the plurality of symbols, where the first measurement information indicates the average value of the channel state information corresponding to the plurality of symbols.

[0037] In this way, to improve the reliability of the ranging feedback, the first node may feedback the channel state information at a designated position (e.g., the Rth symbol) in the first ranging frame.

[0038] In possible designs, the symbols in the first ranging frame use overhead symbol resources in a first type radio frame, the first type radio frame including data symbols and overhead symbols, and at least one channel is the initial carrier channel; or the symbols in the first ranging frame use both data symbol and overhead symbol resources in the first type radio frame, the first type radio frame including data symbols and overhead symbols, and at least one channel is the initial carrier channel.

[0039] For example, the first type of radio frame is a radio frame within a superframe or an SLB.

[0040] This allows existing radio frame resources to be reused for ranging, improving resource utilization.

[0041] In a possible design, symbols in the first ranging frame use data symbols in a second type radio frame, all symbols in the second type radio frame are data symbols, and at least one channel is an initial carrier channel or a channel after frequency hopping.

[0042] This designs a dedicated radio frame type for ranging and improves the reliability of ranging.

[0043] In a possible design, the first node may have the following information: a first indication indicating a type of the first ranging frame; second indication information indicating that the first ranging frame has a CP or does not have a CP; third indication information indicating that the first ranging frame has a normal CP or an extended CP; fourth indication information indicating that the first node feeds back channel state information of at least one channel and / or channel number information of at least one channel; fifth instruction information indicating a measurement start position within the first ranging frame; A sixth indication information indicating that the first node feeds back channel state information corresponding to the Rth symbol in the first ranging frame, where R is a positive integer; seventh indication information indicating that the first node feeds back an average value of channel state information corresponding to a plurality of symbols in the first ranging frame; and Eighth indication information, indicating a first feedback manner in which the first node feeds back channel state information, where the first feedback manner is feeding back channel state information of at least one subcarrier group, or feeding back channel state information of a DC subcarrier, or feeding back channel state information of all valid subcarriers. The device transmits or receives one or more types of

[0044] When the first feedback manner is feeding back the channel state information of at least one subcarrier group, the first node may receive the following information: ninth indication information indicating grouping parameters of at least one subcarrier group; and tenth instruction information indicating how to calculate channel state information for at least one subcarrier group; It may be understood that the device may further transmit or receive one or more of:

[0045] In a specific implementation, the first node transmits or receives one or more of the above-mentioned information in the ranging negotiation phase. For example, the first node is a G node and transmits one or more types of the above-mentioned information. Or, the first node is a T node and receives one or more types of the above-mentioned information transmitted by the G node.

[0046] Of course, the types of instructional information mentioned above are merely examples and not limitations.

[0047] In a possible design, the value of R may be preset or predefined, for example, agreed upon in advance by the first node and the second node or agreed upon in a protocol.

[0048] In a possible design, to obtain calibrated first measurement information, the first node may further calibrate the first measurement information based on calibration information, where the calibration information is determined based on at least one channel, and correspondingly, the first node transmitting the second measurement information based on the first measurement information and the first feedback scheme includes the first node transmitting the second measurement information based on the calibrated first measurement information and the first feedback scheme.

[0049] The calibration information being determined based on at least one channel may be understood as meaning that different channels may have different calibration information, or that the corresponding calibration information is designed separately to suit the channel state information of each channel for calibration.

[0050] This can improve the accuracy of the distance measurement.

[0051] In a possible design, the first node may further transmit a second ranging frame on at least one channel, where the second ranging frame is used by the second node to perform measurements to obtain third measurement information.

[0052] This can implement bilateral ranging interactions and improve the reliability of ranging.

[0053] In a possible design, at least one channel belongs to a first channel group, and the method further includes: the first node receiving a third ranging frame on a second channel group; and the first node measuring the third ranging frame to obtain fourth measurement information, where the second channel group includes one or more channels, and the second channel group has at least one channel different from the first channel group; and the first node transmitting fifth measurement information based on the fourth measurement information and the first feedback scheme.

[0054] In other words, the embodiments of the present application are applied to a frequency hopping ranging scenario, in which the first node and the second node may sequentially perform ranging interactions on different channels (or channel groups) to improve ranging accuracy.

[0055] In a possible design, the first node transmits the second measurement information and the fifth measurement information on at least one primary carrier channel.

[0056] In this way, the measurement information is fed back centrally on the primary carrier channel to improve the ranging interaction efficiency and ensure the reliability of the feedback process.

[0057] In a possible design, the channel state information includes a relative value of a relative reference power level RPL. In addition to transmitting the second measurement information, the first node may further transmit the RPL.

[0058] This increases the dynamic range of the measurement information, so that limited information bits can represent more measurement results, improve the feedback accuracy of the measurement information, and reduce quantification errors.

[0059] In a possible design, in addition to transmitting the second measurement information, RPL, etc., the first node may further transmit the SNR of at least one channel.

[0060] In this way, the SNR may assist the second node in performing ranging calculations, e.g., determining the CSI of the combined channels based on the SNRs of the channels, to further improve the reliability of the ranging calculations.

[0061] According to a second aspect, a ranging method is provided, including: a second node transmitting, on at least one channel, a first ranging frame for ranging; and the second node receiving second measurement information from the first node, where the second measurement information corresponds to the first ranging frame and a first feedback scheme, and the second measurement information is used to determine a ranging result, where the ranging result includes a distance between the first node and the second node.

[0062] In one possible design, the first ranging frame includes at least one symbol, and the first measurement information indicates channel state information of at least one valid subcarrier corresponding to the at least one symbol.

[0063] In a possible design, the first feedback scheme may refer to feedback of channel state information for all valid subcarriers, and the second measurement information and the first measurement information may refer to the same channel state information.

[0064] In a possible design, the first feedback scheme includes feedback of channel state information of a DC subcarrier, the second measurement information includes channel state information of the DC subcarrier corresponding to at least one symbol, and the channel state information of the DC subcarrier is determined by performing interpolation based on channel state information of valid subcarriers adjacent to the DC subcarrier.

[0065] In possible designs, the interpolation includes at least one of linear interpolation, nearest neighbor interpolation, cubic spline interpolation, and / or quadratic interpolation.

[0066] In a possible design, the first feedback scheme indicates feedback of channel state information of at least one subcarrier group, where at least one valid subcarrier corresponding to at least one symbol belongs to the at least one subcarrier group, and the second measurement information includes channel state information of each subcarrier group in the at least one subcarrier group.

[0067] In a possible design, there is one subcarrier group for every M consecutive subcarriers that correspond to at least one symbol, where M is a positive integer, or There is one subcarrier group for every P or L consecutive subcarriers corresponding to at least one symbol, where P and L are positive integers and P≠L.

[0068] In a possible design, the at least one channel includes a first channel and a second channel, where there is one subcarrier group for every Q consecutive subcarriers in the subcarriers corresponding to the first channel, and there is one subcarrier group for every N consecutive subcarriers in the subcarriers corresponding to the second channel, where Q and N are positive integers and Q≠N.

[0069] In a possible design, the channel state information for each subcarrier group may be the mean, median, maximum, or minimum of the channel state information of all valid subcarriers in the subcarrier group or of one subcarrier in the subcarrier group.

[0070] In a possible design, the number of subcarriers included in a subcarrier group is related to the ranging range.

[0071] In a possible design, the symbols in the first ranging frame have a CP or the symbols in the first ranging frame do not have a CP.

[0072] In possible designs, the symbols in the first ranging frame use overhead symbol resources in a first type radio frame, the first type radio frame including data symbols and overhead symbols, and at least one channel is an initial carrier channel; or the symbols in the first ranging frame use both data symbol and overhead symbol resources in the first type radio frame, the first type radio frame including data symbols and overhead symbols, and at least one channel is an initial carrier channel; or the symbols in the first ranging frame use data symbols in a second type radio frame, all symbols in the second type radio frame are data symbols, and at least one channel is an initial carrier channel or a channel after frequency hopping.

[0073] In a possible design, the second node would receive the following information: a first indication indicating a type of the first ranging frame; second indication information indicating that the first ranging frame has a CP or does not have a CP; third indication information indicating that the first ranging frame has a normal CP or an extended CP; fourth indication information indicating that the first node feeds back channel state information of at least one channel and / or channel number information of at least one channel; fifth instruction information indicating a measurement start position within the first ranging frame; A sixth indication information indicating that the first node feeds back channel state information corresponding to the Rth symbol in the first ranging frame, where R is a positive integer; seventh indication information indicating that the first node feeds back an average value of channel state information corresponding to a plurality of symbols in the first ranging frame; and Eighth indication information, indicating a first feedback manner in which the first node feeds back channel state information, where the first feedback manner is feeding back channel state information of at least one subcarrier group, or feeding back channel state information of a DC subcarrier, or feeding back channel state information of all valid subcarriers. , or receive one or more of:

[0074] In a possible design, when the first feedback scheme is feeding back channel state information of at least one subcarrier group, the second node may receive the following information: ninth indication information indicating grouping parameters of at least one subcarrier group; and tenth instruction information indicating how to calculate channel state information for at least one subcarrier group; further transmits or receives one or more of:

[0075] In a possible design, the second node further receives a second ranging frame on at least one channel and measures the second ranging frame to obtain third measurement information, and the second node determines a ranging result based on the second measurement information and the third measurement information, where the ranging result includes a distance between the first node and the second node.

[0076] In a possible design, at least one channel belongs to a first channel group, and the second node may further transmit a third ranging frame for ranging on the second channel group, where the second channel group includes one or more channels, and the second channel group has at least one channel different from the first channel group, and the second node receives fifth measurement information from the first node, where the fifth measurement information corresponds to the fourth measurement information and the first feedback scheme.

[0077] In a possible design, the second node may further receive the second measurement information and the fifth measurement information on the at least one primary carrier channel.

[0078] In a possible design, the value of R is preset or predefined.

[0079] In a possible design, the channel state information includes a relative value of a relative reference power level RPL, and the second node further receives the RPL.

[0080] In a possible design, the second node further receives the SNR of at least one channel.

[0081] According to a third aspect, there is provided a ranging device, comprising a module, unit or technical means configured to implement a method according to the first aspect or any one of the possible designs of the first aspect.

[0082] For example, the device a receiving module configured to receive a first ranging frame on at least one channel; a processing module configured to measure the first ranging frame to obtain first measurement information; a transmitting module configured to transmit second measurement information based on the first measurement information and the first feedback scheme; may include:

[0083] According to a fourth aspect, there is provided a ranging device, comprising a module, unit or technical means configured to implement a method according to the second aspect or any one of the possible designs of the second aspect.

[0084] For example, the device a transmitting module configured to transmit a first ranging frame for ranging on at least one channel; a receiving module configured to receive second measurement information from the first node, the second measurement information corresponding to the first measurement information and the first feedback scheme, the second measurement information being used to determine a ranging result, the ranging result including a distance between the first node and a node where the device is located; and may include:

[0085] According to a fifth aspect, there is provided a ranging device, comprising at least one processor and an interface circuit, the interface circuit configured to receive a signal from a device other than the device and transmit the signal to the processor, or receive a signal from the processor and transmit the signal to the device other than the device, the processor configured to implement, via logic circuits or by executing code instructions, a method according to the first aspect or any one of its possible designs, or a method according to the second aspect or any one of its possible designs.

[0086] According to a sixth aspect, there is provided a computer-readable storage medium, the storage medium storing a computer program or instructions, which, when executed by a communication device, implements a method according to the first aspect or any one of possible designs of the first aspect, or a method according to the second aspect or any one of possible designs of the second aspect.

[0087] According to a seventh aspect, there is provided a computer program product, the computer program product storing instructions which, when run on a computer, enable the computer to perform a method according to the first aspect or any one of the possible designs of the first aspect, or to perform a method according to the second aspect or any one of the possible designs of the second aspect.

[0088] According to an eighth aspect, there is provided a ranging system, comprising: a first node configured to perform a method according to the first aspect or any one of possible designs of the first aspect; a second node configured to perform a method according to the second aspect or any one of possible designs of the second aspect; Includes.

[0089] According to a ninth aspect, there is provided a computer program product storing instructions which, when run on a computer, enable the computer to perform a method according to the first aspect or any one of the possible designs of the first aspect, or enable the computer to perform a method according to the second aspect or any one of the possible designs of the second aspect.

[0090] For the technical effects of the second to ninth aspects, please refer to the technical effects that can be achieved by the corresponding designs in the first aspect, and the details will not be described again in this specification. [Brief explanation of the drawings]

[0091] [Figure 1] 1 is a diagram of a possible application scenario according to an embodiment of the present application; [Figure 2] 1 is a flow chart of a ranging method according to an embodiment of the present application; [Figure 3] FIG. 1 is a diagram of a superframe. [Figure 4] FIG. 2 is a diagram of a ranging frame from a G node and a ranging frame from a T node according to an embodiment of the present application. [Figure 5] FIG. 1 is a diagram of a ranging frame from a G node according to an embodiment of the present application. [Figure 6] FIG. 2 is a diagram of a ranging frame according to an embodiment of the present application. [Figure 7] FIG. 2 is a diagram of a ranging frame according to an embodiment of the present application. [Figure 8] FIG. 10 is a diagram showing a measurement start symbol as the first symbol in a ranging frame. [Figure 9] FIG. 10 illustrates a first node feeding back channel state information corresponding to a first symbol in a ranging frame. [Figure 10] FIG. 10 illustrates a first node feeding back channel state information corresponding to a second symbol in a ranging frame. [Figure 11] FIG. 1 is a diagram of frequency hopping ranging. [Figure 12] 1 is a diagram of a distance measuring device according to an embodiment of the present application; [Figure 13] FIG. 2 is a diagram of another ranging device according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0092] The technical solutions provided in the embodiments of the present application are applicable to various wireless communication scenarios, such as in-vehicle positioning, ranging, angle measurement, or sensing scenarios, indoor positioning, ranging, angle measurement, or sensing scenarios, or other wide-area or local-area wireless communication scenarios, which are not limited in the present application. Specific wireless communication technologies include, but are not limited to, Sparklink, Wireless Fidelity (Wi-Fi), Bluetooth, Bluetooth Low Energy (BLE), or Ultra Wide Band (UWB).

[0093] It will be understood that in embodiments of the present application, similar steps are performed to implement positioning, ranging, angle measurement, sensing, etc. Therefore, any one of the terms may be used to refer to "positioning," "ranging," "angle measurement," "sensing," etc.

[0094] 1 is a diagram of a possible application scenario according to an embodiment of the present application. In an in-vehicle positioning scenario, positioning anchors (also referred to as positioning stations, positioning anchors, anchors, beacons, or measurement nodes), e.g., nodes b, c, d, and e, are deployed at the four vehicle corners on the exterior of the vehicle. At least one positioning anchor, e.g., node a, is deployed inside the vehicle (e.g., on the vehicle rearview mirror or inside the top of the vehicle). A vehicle key is a target to be positioned (i.e., a device to be positioned or a device or label to be measured), e.g., node A. A specific implementation of the vehicle key may be a conventional vehicle key with positioning capabilities, or a mobile phone or wearable device with positioning capabilities. The positioning anchors and / or the vehicle key may transmit and / or receive ranging signals and may measure the received ranging signals to obtain corresponding measurements. The location information of the vehicle key (e.g., its distance relative to the vehicle) may be obtained by calculating the measurements obtained by the positioning anchors and / or the vehicle key.

[0095] In a wireless communication scenario, multiple communication domains may exist within a specific communication area or range. A communication domain is a system formed by a group of communication nodes having a communication relationship and the communication connection relationships (i.e., communication links) between those communication nodes. A communication domain includes one primary communication node (which may be referred to as a primary node or G node for short) and at least one secondary communication node (which may be referred to as a secondary node or T node for short). The primary node, also called an authorizing node, is responsible for managing time-frequency resources within the communication domain and has the function of scheduling resources for communication or positioning between communication nodes within the communication domain. The communication link from the G node to the T node is called a G link or downlink, and the communication link from the T node to the G node is called a T link or uplink.

[0096] The scenario shown in Figure 1 is used as an example. Positioning anchors, vehicle keys, etc. may form one communication domain. The vehicle key may be a primary node (G node), and the positioning anchor is a secondary node (T node), or one positioning anchor is a primary node, and the other positioning anchor and vehicle key are secondary nodes. This is not limited in this application. For ease of explanation, the following uses G nodes and T nodes as illustrative examples. However, the node type is not limited in this application.

[0097] It can be understood that the scenario shown in Figure 1 is just an example. In practical applications, the embodiments of the present application are further applied to other wireless communication scenarios.

[0098] In wireless communication systems based on Orthogonal Frequency Division Multiplexing (OFDM) signals, frequency-hopping ranging techniques are used (i.e., ranging participants can perform ranging interactions on multiple different channels). Measurement results from multiple channels may be combined so that the measurement bandwidth exceeds the bandwidth of a single OFDM signal. This obtains higher ranging resolution, has less multipath interference in multipath-rich environments such as indoor or underground parking lots, and factories, and ultimately obtains higher ranging accuracy.

[0099] In the SparkLink Basic (SLB) version standard, OFDM signals are used as communication signals. In an SLB-based OFDM frequency-hopping ranging system, one of a pair of ranging nodes needs to feed back measurement information (e.g., frequency-domain Channel-State Information (CSI)) for measurement results of a ranging frame (also called a measurement frame) received by the node. The ranging frame includes at least one ranging symbol (e.g., an OFDM symbol) for ranging. For example, in the scenario shown in FIG. 1, a vehicle key may receive a ranging frame, measure the received ranging frame to obtain corresponding measurement information, and then need to feed back the measurement information to a positioning anchor.

[0100] There are several CSI feedback solutions in Wi-Fi systems. However, these solutions are aimed at transmitting precoding in a closed-loop multiple-input multiple-output (MIMO) system. For example, the receiving end feeds back the transmit precoding matrix V to the transmitting end without single-antenna signaling. In addition, the fed back CSI information cannot be for two-way ranging in frequency-hopping ranging (e.g., the CSI cannot correspond to the frequency-hopping channel). Therefore, this solution cannot be applied to measurement information feedback in the aforementioned ranging scenario.

[0101] In view of this, the technical solutions of the embodiments of the present application are provided.

[0102] 2 is a flowchart diagram of a ranging method according to an embodiment of the present application. The method includes the following steps:

[0103] S201: A second node transmits a first ranging frame on at least one channel, and a first node receives the first ranging frame on at least one channel.

[0104] The first node is a G node, the second node is a T node, and correspondingly, the first ranging frame is a ranging frame from the T node. Alternatively, the first node is a T node, the second node is a G node, and correspondingly, the first ranging frame is a ranging frame from the G node.

[0105] In a possible design, the first ranging frame includes at least one symbol, and the symbol may be for ranging, angle measurement, or sensing. For example, in an SLB, the ranging symbol on the G link (i.e., G node link) and the ranging symbol on the T link (i.e., T node link) are a CSI reference signal (CSI-RS) and a sounding reference signal (SRS), respectively. It may be understood that each symbol in the first ranging frame includes information of all subcarriers on at least one channel. The symbols in the first ranging frame may also be referred to as ranging symbols, measurement symbols, etc., and may be used to implement ranging, angle measurement, sensing, etc.

[0106] Optionally, the symbol is an OFDM symbol. For example, in an SLB, in a 20 MHz OFDM symbol having four 80 MHz carriers, each carrier may be used for channel measurement of a 20 MHz carrier channel, and each carrier has 38 effective subcarriers and one direct current (DC) subcarrier. Therefore, an 80 MHz OFDM signal may be used to simultaneously measure four 20 MHz carrier channels, where the four carrier channels form a channel group.

[0107] The configuration of the first ranging frame will be described below.

[0108] In a possible design, symbols in the first ranging frame use overhead symbol resources in a first type radio frame. In other words, the second node transmits symbols in the first ranging frame by using overhead symbol resources in the first type radio frame, and the first node receives symbols in the first ranging frame by using overhead symbol resources in the first type radio frame. The first type radio frame includes data symbols and overhead symbols. The resources are time-frequency resources occupied for symbol transmission.

[0109] For example, the first type of radio frame may be a radio frame of the SLB standard. The SLB standard defines a transmission frame structure of a superframe: the periodicity of the superframe is 1 ms, each superframe includes 48 radio frames, and each radio frame includes some downlink OFDM symbols (or G-link data symbols), some uplink OFDM symbols (or T-link data symbols), some overhead symbols, and an uplink / downlink switching gap (GAP).

[0110] The G link data symbols are for G link data transmission, and the T link data symbols are for T link data transmission. When the transmission direction is not distinguished, the G link data symbols and the T link data symbols are collectively called data symbols. Data transmission includes data information transmission (including user data or upper layer signaling transmission) and another part of the physical layer signal transmission (for example, a second type of data information demodulation reference signal).

[0111] The G-Link system overhead symbols are for G-Link system overhead transmission, and the T-Link system overhead symbols are for T-Link system overhead transmission. When the transmission direction is not distinguished, the G-Link system overhead symbols and the T-Link system overhead symbols are collectively called system overhead symbols. For example, synchronization signals belong to the overhead symbols.

[0112] The overhead symbols may be used by nodes to perform one or more of synchronization, channel sounding, downlink control information (DCI) transmission, etc. The overhead symbols are embedded within each radio frame. There may be one or two available overhead symbols in each radio frame. Correspondingly, there are up to 96 overhead symbols in one superframe (SF).

[0113] When the transmission direction is distinguished, the overhead symbols are classified into two types: the overhead symbols for G-link system overhead transmission are called G-link system overhead symbols (abbreviated as SG), and the overhead symbols for T-link system overhead transmission are called T-link system overhead symbols (abbreviated as ST).When the transmission direction is not distinguished, the G-link system overhead symbols and the T-link system overhead symbols are collectively called system overhead symbols.

[0114] 3 is a diagram of a superframe. The superframe includes 48 radio frames numbered 0 through 47, where SG represents G link system overhead symbols, ST represents T link system overhead symbol resources, G represents G link data symbol resources, and T represents T link data symbol resources. In FIG. 3, each radio frame includes one SG symbol or one ST symbol, and the 48 radio frames in the superframe include a total of 48 overhead symbols.

[0115] In periodic superframe transmission, nodes G and T use reference signals such as a First Training Signal (FTS) and a Second Training Signal (STS) to perform timing and frequency synchronization at the beginning of the first superframe. Synchronization signals may be inserted in each superframe to maintain timing and frequency synchronization. Thus, overhead symbols in subsequent superframes may be used for transmitting ranging symbols.

[0116] For example, Figure 4 is a diagram of a ranging frame of a G node and a ranging frame of a T node when each radio frame includes one SG or ST symbol. When each radio frame includes one SG symbol or one ST symbol, one ranging frame may include L overhead symbols, where the ranging frame of the G node includes L SG symbols and the ranging frame of the T node includes L ST symbols. It can be understood that one ranging interaction process includes at least one ranging frame of a G node and at least one ranging frame of a T node.

[0117] For example, FIG. 5 is a diagram of a ranging frame of a G node where each radio frame contains two SG or ST symbols.

[0118] Of course, Figures 4 and 5 are merely examples, and in practical applications the ranging frame may alternatively be in another form.

[0119] In the above design, it may be understood that at least one channel is an initial carrier channel (or an initial carrier channel group) of the first node and the second node. The initial carrier channel (or the initial carrier channel group) represents an operating carrier channel (or an operating carrier channel group) after the G node or the T node completes association, i.e., a carrier channel (or an operating carrier channel group) on which ranging negotiation is performed.

[0120] It will be understood that before performing ranging interaction, the G node and the T node must first perform association. A specific operation process includes: the G node sending an association request to the T node, and the T node returning an association response to the G node; or the T node sending an association request to the G node, and the G node returning an association response to the T node. If the G node and the T node do not have a security context, the association request may specifically be an "associationRequestNonSec (associationRequestNonSec)" message, and the association response may be an "AssociationSetupNonSec (AssociationSetupNonSec)" message. Alternatively, if the G node and the T node have a security context, the association request may be an "associationRequestWithSec (associationRequestWithSec)" message, and the association response may be an "AssociationSetupWithSec (AssociationSetupWithSec)" message.

[0121] Optionally, the initial carrier channel is the channel (or channel group) having the highest frequency among all available channels (or available channel groups) of the first node and the second node.

[0122] In the initial carrier channel, the symbols in the ranging frame use the overhead symbol resources in the defined radio frame, which can improve resource utilization, does not affect communication between G and T nodes, and has strong backward compatibility.

[0123] In another possible design, symbols in the first ranging frame use resources of data symbols in the second-type radio frame. In other words, the second node transmits symbols in the first ranging frame by using resources of data symbols in the second-type radio frame, and the first node receives symbols in the first ranging frame by using resources of data symbols in the second-type radio frame. All symbols in the second-type radio frame are data symbols, and at least one channel is an initial carrier channel or a channel after frequency hopping.

[0124] The second type radio frame may differ from the first type radio frame in that the symbols in the second type radio frame are all configured as T data symbols or all configured as G data symbols. The second type radio frame may have no SG symbols, ST symbols, or gaps, and an uplink / downlink switching gap is implemented between the radio frame intervals of the G node and the T node.

[0125] In a specific implementation, all symbols in the second-type radio frame may be used for ranging. Therefore, the structure of the ranging frame may match the structure of the second-type radio frame. Specifically, all symbols in the ranging frame use the resources of all symbols in the second-type radio frame. In other words, the ranging frame is a second-type radio frame, i.e., all symbols in the second-type radio frame form the ranging frame. Therefore, in this design, the second-type radio frame and the ranging frame may be interchangeable.

[0126] In addition to the Channel-State Information-Reference Signal (CSI-RS) and the Sounding Reference Signal (SRS), the OFDM symbols in the second-type radio frame may further use the FTS or STS. When the transmitting node (e.g., the second node) of the pair of the ranging node transmits any one of the aforementioned ranging symbols, a reference signal known to the receiving node is transmitted, so that the receiving node may perform demodulation or channel estimation on the reference signal to obtain CSI. In the receiving node (e.g., the first node), the channel frequency response values ​​(complex values, abbreviated as IQ values) of corresponding frequencies corresponding to the subcarriers corresponding to the OFDM symbols for the sounding channel (or referred to as reference signals) are referred to as the frequency-domain CSI of the sounding channel.

[0127] The second type of radio frame may or may not support a cyclic prefix (CP). For example, if the symbol type is specifically a CSI-RS or SRS symbol, the symbol may or may not have a CP. For example, if the symbol type is specifically an FTS or STS symbol in an SLB, the symbol does not have a CP. When multiple OFDM symbols (e.g., FTS or STS symbols) without a CP are transmitted consecutively, the previous symbol may be used as the cyclic prefix of the next symbol due to the natural cyclic shift characteristic between adjacent symbols. Because the duration of one OFDM symbol is much longer than the duration of one CP, the ability to accommodate multipath delay spread is stronger and the requirement for time synchronization between transceiver nodes is relaxed. This can reduce the overhead for time synchronization before a ranging frame.

[0128] Furthermore, if the second type of radio frame has a CP, the CP may be classified into a normal CP and an extended CP. The extended CP is used in scenarios with a large ranging range. When the G node and the T node measure multiple carrier channels through frequency hopping, the CP configuration of all carrier channels is the same.

[0129] As shown in Figure 6, the gap between the second-type radio frame of the G node and the second-type radio frame of the T node may occupy the last OFDM symbol in the first-transmitted second-type radio frame. Alternatively, each second-type radio frame may accommodate 10 OFDM symbols without a CP, and the gap appears between two second-type radio frames (i.e., the GAP does not occupy time in the second-type radio frame). When a CP-OFDM symbol (i.e., an OFDM symbol with a CP) is used as a ranging symbol, each radio frame may use the same method as the existing radio frame structure in SLB, i.e., one radio frame has eight normal CP-OFDM symbols or seven extended CP-OFDM symbols.

[0130] It can be understood that the second type of radio frame provided in the above design is not a defined radio frame for communication between the G node and the T node, and therefore is applicable to all channels. In other words, at least one channel may be the initial carrier channel (or initial carrier channel group) of the first node and the second node, or may be a channel after frequency hopping.

[0131] This design defines a new radio frame structure for the transmission of ranging symbols without affecting the transmission of the original radio frame.

[0132] In another possible design, symbols in the first ranging frame use both data symbol and overhead symbol resources in a first-type radio frame, where the first-type radio frame includes data symbols and overhead symbols. In other words, the second node transmits symbols in the first ranging frame by using data symbol and overhead symbol resources in the first-type radio frame, and the first node receives symbols in the first ranging frame by using data symbol and overhead symbol resources in the first-type radio frame. For the structure of the first-type radio frame, please refer to the related description of FIG. 3. Details will not be described again herein.

[0133] From the foregoing description, it can be learned that in periodically transmitted superframes, except for the first superframe, overhead symbols in subsequent superframes may be used for transmitting ranging symbols. If the G and T nodes have remaining data symbol resources in subsequent superframes for communication, the remaining data symbol resources may be used for transmitting ranging symbols. For example, FIG. 7 is a diagram of a possible ranging frame. The data symbol resources for ranging symbol transmission may be agreed upon by the G and T nodes in the ranging negotiation phase and / or may be indicated by using preamble information transmitted before the ranging frame.

[0134] In the foregoing designs, it may be understood that the at least one channel is an initial carrier channel (or initial carrier channel group) of the first node and the second node.

[0135] In the primary carrier channel, the ranging symbols in the ranging frame are transmitted by using overhead and data symbol resources in the defined radio frame, which improves resource utilization without affecting communication between the G and T nodes, enables ranging and positioning functions to be performed in parallel with communication functions, and has strong backward compatibility.

[0136] The above describes several possible types of the first ranging frame. In practical application, before transmitting the first ranging frame, the first node and the second node need to determine the type of the first ranging frame.

[0137] In one possible design, the first node and the second node may determine a type of the first ranging frame during the ranging negotiation phase. For example, the G nodes of the first node and the second node may configure a type of the first ranging frame and transmit first indication information indicating the type of the first ranging frame.

[0138] Specifically, if the first node is a G node, the first node sends the first instruction information and the second node receives the first instruction information; or if the first node is a T node, the second node sends the first instruction information and the first node receives the first instruction information.

[0139] Optionally, the first instruction information may be included in a first message to be transmitted in the ranging negotiation phase, so that after receiving the first instruction information, the node receiving the first message can determine the type of ranging frame that needs to be exchanged with the node transmitting the first message to prepare to transmit or receive the ranging frame in advance.

[0140] For example, the ranging frame shown in Fig. 4 is defined as Type 1, the ranging frame shown in Fig. 5 is defined as Type 2, the ranging frame shown in Fig. 6 is defined as Type 3, and the ranging frame shown in Fig. 7 is defined as Type 4. In this case, the first node may send or receive first instruction information, where the first instruction information indicates any one of Type 1, Type 2, Type 3, and Type 4.

[0141] In addition to indicating the type of ranging frame in the ranging negotiation phase, the G node may further indicate the type of ranging frame by using radio frame structure information in preamble information transmitted before the ranging frame. For example, the preamble information transmitted by the G node indicates a specific number of radio frame structures to determine the structure of the ranging frame.

[0142] For example, Table 1 below shows example radio frame structures for various G-link and T-link symbol ratios configured based on the extended CP. Radio frame structures 0 through 11 indicate that the radio frame has both G-link and T-link ranging symbols, while radio frame structures 12 and 13 indicate that the radio frame has only G-link or T-link ranging symbols and may be for transmission of ranging frame type 3. Radio frame structures configured based on the normal cyclic prefix are similar to those in Table 1, except that the resources of a radio frame with 8 OFDM symbols are used to carry the G-link and T-link ranging symbols.

[0143] [Table 1]

[0144] Furthermore, before transmitting the first ranging frame, the first node and the second node need to further determine whether the first ranging frame has a CP.

[0145] In a possible design, the first node and the second node may determine whether the first ranging frame has a CP during the ranging negotiation phase. For example, the G nodes of the first node and the second node may configure the first ranging frame to have a CP or not have a CP and send second indication information indicating whether the first ranging frame has a CP or not have a CP.

[0146] In practical applications, it may be understood that the first indication information and the second indication information may be the same indication information, that is, one indication information may indicate both the frame type and whether a CP exists. For example, the first indication information indicates that the frame type is the ranging frame (Type 1) shown in FIG. 4 and that this type of ranging frame does not have a CP. Therefore, additional indication information may not be used to indicate whether a CP exists.

[0147] Of course, the first and second indications may alternatively be different indications. For example, the first indication indicates that the frame type is the ranging frame (Type 2) shown in FIG. 5, and that this type of ranging frame may or may not have a CP. Therefore, the second indication may additionally be configured to indicate whether the first ranging frame has a CP.

[0148] Optionally, both the first indication information and the second indication information are carried in the first message, which can reduce resource overhead.

[0149] Furthermore, if the first ranging frame has a CP, before transmitting the first ranging frame, the first node and the second node need to further determine whether the CP of the first ranging frame is a normal CP or an extended CP.

[0150] In a possible design, the first node and the second node may determine whether the first ranging frame has a normal CP or an extended CP during the ranging negotiation phase. For example, the G nodes of the first node and the second node configure whether the first ranging frame has a normal CP or an extended CP and send third indication information indicating that the first ranging frame has a normal CP or an extended CP.

[0151] Optionally, the third indication information may also be carried in the first message, which can further reduce resource overhead.

[0152] S202: The first node measures a first ranging frame to obtain first measurement information.

[0153] In one example, when an OFDM symbol is used as a ranging symbol, an OFDM signal with an effective bandwidth of approximately 20 MHz may be called a carrier (a channel for transmitting a carrier OFDM signal is called a carrier channel), and the center frequency (i.e., DC subcarrier) of the 20 MHz OFDM signal is called a carrier frequency. That is, one carrier includes 39 consecutive subcarriers, and the 39 subcarriers are sequentially numbered #0, #1, ..., and #38 in ascending order of corresponding frequencies. Subcarrier #19 is a direct current (DC) subcarrier, and the other 38 subcarriers excluding the DC subcarrier are called effective subcarriers. The G node and the T node may operate on multiple carrier channels, and multiple carrier channels form one carrier channel group (corresponding to one channel group). For ease of explanation, the carrier channel is abbreviated to a channel in the embodiments of the present application.

[0154] It should be understood that when measuring the first ranging frame, the first node actually measures each valid subcarrier, and therefore the first measurement information obtained by the measurement may indicate channel state information of a frequency corresponding to at least one valid subcarrier of at least one symbol corresponding to the first ranging frame.

[0155] For ease of explanation, in this specification, "channel state information of a frequency corresponding to a subcarrier" may also be referred to as "channel state information of a subcarrier."

[0156] Additionally, "channel state information" herein may also be referred to as "CSI," "CSI information," "CSI feedback information," "feedback information," and the like.

[0157] In a specific implementation, after performing a fast Fourier transform (FFT) operation on the received data in the time domain, the receiver of the first node performs demodulation and / or channel estimation on a known modulation sequence such as CSI-RS, SRS, etc. to obtain a channel frequency response value (or called a channel estimate) for each valid subcarrier, which may be represented by a complex value (such as an I value and a Q value, or IQ value for short), and these IQ values ​​may be referred to as frequency-domain channel state information (i.e., frequency-domain CSI). Because frequency-domain channel state information is primarily discussed herein, the frequency-domain channel state information may hereinafter be referred to as channel state information (CSI) for short.

[0158] In a possible design, in the ranging negotiation phase, after performing measurements (i.e., after determining that the measurements are frequency-domain CSI measurements), the first node and the second node decide to feed back channel state information of at least one channel. For example, the G node (the first node or the second node) further sends fourth indication information indicating that the first node will feed back channel state information of at least one channel and / or channel number information of at least one channel. Optionally, in a frequency-hopping ranging scenario, the fourth indication information may further indicate a carrier channel number and / or a subcarrier number corresponding to the fed-back channel state information. The carrier channel number may represent a channel number of a carrier (20 MHz carrier), such that after frequency-hopping measurements of multiple channels are completed, channel state information corresponding to the multiple channels can be fed back together, and the channel state information can correspond to the channel to which the channel state information belongs based on the channel number, and the channel state information of the multiple channels is combined in frequency-hopping ranging signal processing.

[0159] From the above description, it can be learned that the first ranging frame may have one ranging frame symbol or may have multiple ranging symbols. Therefore, if the first ranging frame has multiple ranging frame symbols, before measuring the first ranging frame, the first node needs to determine the symbol to be measured or the symbol to start measuring.

[0160] In a possible design, the symbol in the first ranging frame has a CP, and the first node may perform measurements starting from the first symbol in the first ranging frame. For example, FIG. 8 illustrates a diagram in which the measurement start symbol is the first symbol. The channel state information corresponding to radio frame 1 and radio frame 2 is the channel state information corresponding to the first symbol.

[0161] In another possible design, the symbols in the first ranging frame may not have a CP, and the first node may perform measurements starting from the second symbol in the first ranging frame. It can be understood that the first ranging frame does not have a CP to resist multipath interference. Therefore, the first symbol may be sacrificed to resist multipath interference and fulfill the role of a CP. This improves measurement accuracy.

[0162] In another possible design, the first node may perform measurements starting from a specified symbol in the first ranging frame based on instructional information, a preset configuration, a preset agreement, or the like.

[0163] For example, the first node and the second node may configure a measurement start position (or measurement start symbol) in the ranging negotiation phase. For example, the G nodes of the first node and the second node may transmit a fifth indication indicating a measurement start position (i.e., a symbol where the measurement starts, for example, the Rth symbol, where R is a positive integer and a fixed value) within the first ranging frame.

[0164] For example, the protocol specifies, or the first node and the second node agree on, the measurement start position within the first ranging frame (i.e., the symbol where the measurement starts, e.g., the Rth symbol, where R is a positive integer and a fixed value once agreed upon).

[0165] Furthermore, when measuring multiple symbols in the first ranging frame, the first node needs to determine the channel state information corresponding to the symbols that is fed back by the first node.

[0166] In a possible design, when the first ranging frame includes multiple symbols, the first node determines channel state information corresponding to the Rth symbol of the first ranging frame based on channel state information corresponding to the multiple symbols, where R is a positive integer, and the first measurement information indicates channel state information corresponding to the Rth symbol.

[0167] The first node determining channel state information corresponding to the Rth symbol in the first ranging frame based on channel state information corresponding to multiple symbols can be understood as: when the first node measures multiple symbols in the first ranging frame and feeds back channel state information corresponding to the Rth symbol of the first ranging frame, channel state information corresponding to another symbol in the first ranging frame other than the Rth symbol may be converted into channel state information corresponding to the Rth symbol, or channel state information corresponding to another symbol in the first ranging frame other than the Rth symbol may be used to assist in estimating channel state information corresponding to the Rth symbol. For example, once the channel state information corresponding to the Rth symbol is determined, the channel state information corresponding to the Rth symbol is converted into estimated CSI corresponding to the Rth symbol based on information such as CSI obtained by calculation of at least one symbol after the Rth symbol, symbol duration, and carrier frequency offset (CFO), thereby correcting the CSI obtained by measuring the Rth symbol. This can improve the signal-to-noise ratio and accuracy of the CSI corresponding to the Rth symbol.

[0168] Through indication or prior agreement, one node (e.g., the first node) of the ranging parties feeds back CSI corresponding to the Rth symbol, and the other node (e.g., the second node) of the frequency hopping ranging may combine CSI corresponding to symbols having the same resource sequence number when combining the CSI of the two nodes (e.g., may combine CSI corresponding to the Rth symbol in the first ranging frame with CSI corresponding to the Rth symbol in the second ranging frame, where the second ranging frame is the ranging frame transmitted by the first node and used for measurement by the second node).

[0169] The resource sequence number indicates the position of a symbol within a ranging frame. For example, if a ranging frame includes N symbols, the resource sequence numbers of the N symbols may indicate the sequence in which the N symbols appear in the time domain and indicate the symbols within the ranging frame. For example, the resource sequence number of the first symbol may be 0, the resource sequence number of the second symbol may be 1, ..., and the resource sequence number of the Nth symbol may be N-1. However, this is not a limitation but merely an example.

[0170] This can avoid CSI corresponding to symbols with different resource sequence numbers being combined during frequency hopping ranging.

[0171] In one example, as shown in FIG. 9, if a symbol in the first ranging frame has a CP, the first node feeds back channel state information corresponding to the first symbol, i.e., the first measurement information indicates the channel state information corresponding to the first symbol.

[0172] The measurement result of another symbol in the frame should be transformed into the measurement result of the first symbol. For example, when the frequency-domain CSI of an OFDM subcarrier is measured, the phases of the same subcarrier in the first symbol and the second symbol are different due to residual carrier frequency offset (CFO). Therefore, the position of the measurement symbol must be specified, and the phase of the other symbol is aligned and estimated based on the occurrence time of the first symbol. Thus, the channel state information corresponding to another symbol in the radio frame other than the first symbol is transformed into the first ranging symbol, and the channel state information of the first symbol is corrected. Finally, the channel state information corresponding to the first symbol is fed back.

[0173] In one example, as shown in FIG. 10, if a symbol in the first ranging frame does not have a CP, the first node feeds back channel state information corresponding to the second symbol, i.e., the first measurement information indicates the channel state information corresponding to the second symbol.

[0174] Of course, the above two cases are merely examples. In practical applications, R may alternatively have other values, which is not limited in this application.

[0175] In another possible design, when the first ranging frame includes multiple symbols, the first node determines a statistical value, such as a maximum value, a minimum value, or an average value, of the channel state information corresponding to the multiple symbols based on the channel state information corresponding to the multiple symbols, and the first measurement information indicates the statistical value of the channel state information corresponding to the multiple symbols.

[0176] To ensure that the measurement interaction between the first node and the second node is successful, before transmitting the first ranging frame, the first node and the second node need to further determine channel state information corresponding to the symbols fed back by the first node.

[0177] For example, in the ranging negotiation phase or when the preamble information is transmitted, the G node (the first node or the second node) transmits the seventh instruction information indicating that the first node will feed back an average value of channel state information corresponding to multiple symbols in the first ranging frame. By transmitting the average value of channel state information corresponding to multiple symbols, channel state information with a high SNR can be obtained with a simple processing method, and combining CSI corresponding to symbols with different resource sequence numbers can be avoided. For example, in the ranging negotiation phase or when the preamble information is transmitted, the G node (the first node or the second node) transmits the sixth instruction information, etc. indicating that the first node will feed back channel state information corresponding to the Rth symbol in the first ranging frame. By transmitting the channel state information corresponding to the Rth symbol, it is possible to feed back channel state information corresponding to a specified symbol and avoid non-coherent combining gain caused by combining CSI corresponding to different resource sequence numbers.

[0178] During frequency hopping ranging, after the G node sends the sixth or seventh instruction information, the first node can maintain the same feedback scheme on each channel (group) in frequency hopping, which can coherently combine CSI on different channels and obtain high bandwidth gain of frequency hopping ranging.

[0179] S203: The first node sends second measurement information based on the first measurement information and the first feedback manner, and the second node receives the second measurement information from the first node.

[0180] In an optional implementation, after obtaining the first measurement information, the first node may further calibrate the first measurement information to eliminate non-ideal characteristics introduced by the radio frequency transceiver channel and the antenna and included in the first measurement information, so that the first node transmits second measurement information based on the calibrated first measurement information and the first feedback scheme.

[0181] For example, the first node calibrates the first measurement information based on calibration information to obtain calibrated first measurement information, where the calibration information is determined based on at least one channel.

[0182] The calibration information being determined based on at least one channel may be understood as meaning that for the channel state information of a channel, calibration needs to be performed based on the calibration information corresponding to the channel, and different channels may correspond to different calibration information.

[0183] For example, the IQ value of a single subcarrier may be defined as the IQ value of the subcarrier at which the Rth symbol in the first ranging frame arrives at the antenna connector of the first node. During implementation, to obtain the IQ value of the subcarrier at the antenna connector, loopback measurements of different frequency bands or channels and / or baseband processing delays need to be calibrated at baseband against the IQ value of the subcarrier obtained by estimating the original received signal.

[0184] This can improve the accuracy of the channel state information and improve the ranging accuracy.

[0185] In this embodiment of the present application, the first node obtains the first measurement information through measurement, but the form of the measurement information finally fed back by the first node (whether to feed back the first measurement information directly or to feed back the first measurement information after further processing the first measurement information) needs to be determined based on the first feedback manner.

[0186] The first feedback scheme may belong to a predefined or configured feedback scheme set, which defines a number of different feedback schemes.

[0187] Below we list some possible feedback methods.

[0188] 1. The first feedback method indicates feedback of channel state information of all valid subcarriers. In this case, the second measurement information and the first measurement information indicate the same channel state information. In other words, the second measurement information also indicates channel state information of at least one valid subcarrier corresponding to at least one symbol in the first ranging frame.

[0189] For example, if the number of at least one channel is 1, the first measurement information may indicate channel state information of 38 valid subcarriers on that channel, and the second measurement information also indicates channel state information of 38 valid subcarriers on that channel.

[0190] For example, if at least one channel is a plurality of channels, the first measurement information may indicate channel state information of 38 valid subcarriers on each of the plurality of channels, and the second measurement information also indicates channel state information of 38 valid subcarriers on each of the plurality of channels.

[0191] In a specific implementation, the second measurement information may be carried in a CSI report message. For example, Table 2 shows an example of a CSI report message corresponding to a 20 MHz carrier in the first feedback manner.

[0192] It can be seen that when the ranging frame is carried by multiple 20 MHz carriers, the CSI feedback for each 20 MHz is shown in Table 2. For the three ineffective subcarriers used as spacing between adjacent 20 MHz carriers, no modulation signal is present, so CSI cannot be measured, which may not be used as part of the CSI for feedback, which may reduce the amount of CSI feedback data.

[0193] [Table 2]

[0194] In frequency hopping ranging, in the CSI report message shown in Table 2, the carrier channel number (ChannelNumber) and / or subcarrier number corresponding to the fed back CSI should be indicated based on the fourth indication information. ChannelNumber in this specification may refer to the channel number corresponding to the carrier, i.e., the channel corresponding to the reported CSI (CSI value corresponding to subcarrier 0# to 38#).

[0195] 2. The first feedback scheme indicates feedback of channel state information of a DC subcarrier. In this case, the second measurement information and the first measurement information indicate different channel state information, and the second measurement information is determined based on the first measurement information. The second measurement information includes channel state information of a DC subcarrier corresponding to at least one symbol, and the channel state information of the DC subcarrier is determined by performing interpolation based on channel state information of valid subcarriers adjacent to the DC subcarrier. The interpolation includes at least one of linear interpolation, nearest neighbor interpolation, cubic spline interpolation, and / or quadratic interpolation. This is not limited in the present application.

[0196] From the above description, it can be learned that each channel includes 38 valid subcarriers and one DC subcarrier. Therefore, if at least one channel is a plurality of channels, the second measurement information includes channel state information of the DC subcarriers on the plurality of channels. The channel state information of each DC subcarrier is determined by performing interpolation based on the channel state information of other valid subcarriers on the channel to which the DC subcarrier belongs.

[0197] For example, on a 2.4 GHz channel, the DC subcarrier spacing is 5 MHz, and the unambiguous distance (i.e., the maximum ranging range) is 60 m. For example, on 2.4 GHz and 5 GHz channels, the minimum DC subcarrier spacing is 5 MHz, and the unambiguous distance is again 60 m. It can be learned that when the DC subcarrier spacing is 5 MHz, a ranging range of 60 m can be supported by feeding back channel state information of the DC subcarrier. This satisfies most short-distance ranging scenarios.

[0198] 3. The first feedback method indicates group feedback, i.e., the first feedback method indicates feedback of channel state information of at least one subcarrier group, where at least one valid subcarrier corresponding to at least one symbol belongs to at least one subcarrier group, and the second measurement information includes channel state information of each subcarrier group in the at least one subcarrier group, in which the second measurement information and the first measurement information indicate different channel state information, and the second measurement information is determined based on the first measurement information.

[0199] It may be understood that in this document, the number of subcarriers included in a subcarrier group may also be referred to as a subcarrier grouping interval, a subcarrier group spacing, etc. The grouping interval may indicate a grouping scheme, for example, the number of subcarriers that form a subcarrier group.

[0200] During grouping, only valid subcarriers may be grouped, or both valid subcarriers and DC subcarriers may be grouped. In other words, a subcarrier group may include only valid subcarriers, or both valid subcarriers and DC subcarriers. This is not limited in the present application. After the valid subcarriers are grouped, CSI of only one subcarrier may be fed back in each subcarrier group. This can reduce the amount of CSI data to be fed back (i.e., the amount of data of the second measurement information).

[0201] Below we list some possible grouping schemes:

[0202] Scheme 1: There is one subcarrier group for every M consecutive subcarriers corresponding to at least one symbol, where M is a positive integer.

[0203] For example, for any one of at least one channel, every third consecutive subcarrier of the 39 subcarriers on the channel may be grouped into one group, obtaining a total of 13 subcarrier groups, but this is by way of example only and not limitation.

[0204] This grouping method is simple and easy to implement.

[0205] Scheme 2: There is one subcarrier group for every P or L consecutive subcarriers corresponding to at least one symbol, where P and L are positive integers and P≠L.

[0206] It should be noted here that subcarrier groups containing P subcarriers and subcarrier groups containing L subcarriers coexist, i.e., two different grouping intervals can exist simultaneously.

[0207] For example, for any one of at least one channel (corresponding to a bandwidth of 20 MHz), every fourth or third consecutive subcarrier of the 39 subcarriers on the channel may form one subcarrier group, obtaining 12 groups, where the number of subcarriers in three groups is 4 and the number of subcarriers in the other nine groups is 3. However, this is merely an example and not a limitation.

[0208] This grouping scheme can ensure that all subcarriers can be grouped into subcarrier groups, improving the reliability of the solution.

[0209] Optionally, the difference between P and L is 1 or 2.

[0210] For example, for subcarriers on a channel, some subcarriers are grouped by using every P consecutive subcarriers as one subcarrier group, and other subcarriers are grouped by using every L consecutive subcarriers as one subcarrier group, where L = P-2, and the subcarrier group with L subcarriers includes the DC subcarrier. The advantage of doing this is that valid subcarriers on either side of the DC subcarrier appear in pairs. For example, subcarriers #0, #16, and #18 and subcarriers #38, #22, and #20 are used as subcarrier pairs, respectively, and the subcarriers that appear in pairs are selected to facilitate blank DC subcarriers and interpolation between adjacent 20 MHz carriers. As shown in Table 3, when P = 4, L = 2 is set to the position including DC subcarrier #19, and subcarriers #18 and #20 are selected, so that all selected subcarriers are symmetrical with respect to the DC subcarrier. Symmetric subcarriers are selected to help the processing algorithm eliminate DC effects and improve the accuracy of the combined multi-channel CSI.

[0211] In a specific example, if P=4 and L=3, this indicates that every four consecutive (P) subcarriers or every three consecutive subcarriers within one carrier form one subcarrier group of the first granularity.

[0212] Table 3 shows an example of a CSI report message for the first feedback scheme when the subcarrier grouping corresponds to 2 (P = L = 2), the subcarrier grouping corresponds to 4 (P = 4, L = 3), and the subcarrier grouping corresponds to 8 (P = 8, L = 6). In this case, one subcarrier is designated within each subcarrier group as a representative of the subcarrier group for feedback. L is used to account for an exception caused by the inability to uniformly group subcarriers near the DC subcarrier. Therefore, the subcarrier grouping parameter may be represented by only P, and L may not be displayed.

[0213] [Table 3]

[0214] In this embodiment of the present application, when at least one channel is a plurality of channels, the grouping intervals of the subcarriers corresponding to all the channels (or the subcarrier group interval, which is equal to the amount P of subcarriers included in the subcarrier group) may be the same (i.e., may be uniformly grouped) or different (i.e., may be non-uniformly grouped), which is not limited in the present application.

[0215] For example, the at least one channel includes a first channel and a second channel, where there is one subcarrier group for every Q consecutive subcarriers in the subcarriers corresponding to the first channel, and there is one subcarrier group for every N consecutive subcarriers in the subcarriers corresponding to the second channel, where Q and N are positive integers and Q≠N.

[0216] When the G node configures the fed-back parameters by using CSI, a uniform grouping mode or a non-uniform grouping mode should be indicated in the CSI configuration information. If the uniform grouping mode is indicated, the subcarrier grouping parameter of all measured channels is P. If the non-uniform grouping mode is used, a different P value indicates the grouping parameter of the channel. For example, if a total of four channels (e.g., frequency hopping measurements) are measured, four different P values ​​may be configured. Channel 1: P=1 (indicating that the subcarrier grouping interval on channel 1 is 1, i.e., full feedback). Channel 2: P=1 (indicating that the subcarrier grouping interval on channel 2 is 1, i.e., full feedback) Channel 3: P=2 (indicating that the subcarrier grouping interval on channel 3 is 2, i.e., the grouping parameter P=2) Channel 4: P=4 (indicating that the subcarrier grouping interval on channel 3 is 2, i.e., grouping parameter P=4)

[0217] In the above-described method 1 or method 2, the channel state information of each subcarrier group may be a statistical value (e.g., average, median, maximum, or minimum) of the channel state information of all valid subcarriers in the subcarrier group, which can reduce the amount of feedback.

[0218] In the above-described Scheme 1 or Scheme 2, the channel state information of each subcarrier group may be the channel state information of one subcarrier in the subcarrier group, for example, the channel state information of the first subcarrier, the last subcarrier, or an intermediate subcarrier, which can reduce the amount of feedback, has a simple implementation form, is easy to implement, and has high reliability.

[0219] In the above-mentioned methods 1 and 2, all subcarriers are grouped. In practical applications, only some subcarriers may be selected for grouping. For example, In Method 3, G subcarriers are used as a comb to divide the subcarrier group. Specifically, valid subcarriers selected from every G consecutive subcarriers are used separately as subcarrier groups, i.e., each subcarrier group contains only one subcarrier.

[0220] For example, 39 subcarriers on one channel may be divided into eight subcarrier groups by using five subcarriers as a comb, with the subcarriers included in each subcarrier group being subcarriers #0, #5, #10, #15, #20, #25, #30, and #35, in that order.

[0221] In Scheme 3, the channel state information of each subcarrier group is the channel state information of the subcarriers included in the subcarrier group.

[0222] In the above-mentioned Schemes 1 and 2, if the channel state information of each subcarrier group is the channel state information of one valid subcarrier in the subcarrier group, it can be understood that the feedback effect ultimately achieved in Schemes 1 and 2 is similar to that of Scheme 3, that is, the channel state information of each subcarrier group is essentially the channel state information of one valid subcarrier.

[0223] In this embodiment of the present application, before transmitting the first ranging frame, the first node and the second node need to further determine a first feedback scheme in which the first node feeds back the channel state information.

[0224] In a possible design, the first node and the second node may determine a first feedback scheme for the first node to feedback channel state information during the ranging negotiation phase. For example, the G nodes of the first node and the second node may determine a first feedback scheme and transmit eighth indication information indicating the first feedback scheme for the first node to feedback channel state information, where the first feedback scheme is feedbacking channel state information of at least one subcarrier group, feedbacking channel state information of a DC subcarrier, or feedbacking channel state information of all enabled subcarriers.

[0225] Furthermore, when the first feedback scheme is feeding back the channel state information of at least one subcarrier group, the first node and the second node need to further determine the grouping parameters of the at least one subcarrier group, the calculation scheme of the channel state information of the at least one subcarrier group, etc.

[0226] The grouping parameter indicates how to divide the subcarrier groups. For example, the grouping parameter may indicate that the grouping scheme is Scheme 1, Scheme 2, Scheme 3, etc. Optionally, the grouping parameter further indicates a specific grouping interval (i.e., the number of subcarriers included in a subcarrier group) in the corresponding grouping scheme, for example, M or P and L in the above description. Optionally, the grouping parameter may further indicate whether different channels are grouped uniformly or unevenly. If different channels are grouped unevenly, the grouping parameter may indicate the grouping intervals of different channels, for example, the values ​​of Q and N in the above example. Of course, the above are only some examples of grouping parameters. In practical applications, any parameter indicating a grouping method may belong to the grouping parameter.

[0227] The calculation method indicates how to determine the channel state information of the subcarrier groups, for example, the channel state information of each subcarrier group is the average value of the channel state information of all valid subcarriers in the subcarrier group, or the channel state information of each subcarrier group is the channel state information of one subcarrier in the subcarrier group.

[0228] In a possible design, the first node and the second node may determine grouping parameters for the at least one subcarrier group, a calculation method for channel state information for the at least one subcarrier group, etc. during the ranging negotiation phase.

[0229] For example, the G nodes of the first node and the second node determine calculation methods for grouping parameters of at least one subcarrier group and channel state information of at least one subcarrier group, and send ninth instruction information and tenth instruction information, respectively indicating the calculation methods for the grouping parameters of the at least one subcarrier group and the channel state information of the at least one subcarrier group.

[0230] Optionally, the ninth and / or tenth indications and the eighth indication may be carried in the same message, for example, the second message. This can reduce resource overhead. The second message may be the same as or different from the first message. This is not limited in the present application.

[0231] In a specific implementation process, the number of subcarriers included in a subcarrier group may be related to a ranging range. For example, a larger ranging range is expected to indicate a smaller number of subcarriers included in a subcarrier group. Alternatively, a smaller ranging range is expected to indicate a larger number of subcarriers included in a subcarrier group.

[0232] For example, D max represents the maximum distance measurement range, and B SC If σ denotes the number of subcarriers included in the subcarrier group, the following relationship is satisfied: D max =c / 2B SC , in the formula, The value of c is the speed of light 3 × 10 8 m / s. For example, B SC = 480kHz, the corresponding maximum distance measurement range is 312.5m. Or, B SC = 480 × 4 kHz, the corresponding maximum range is 78.125 m.

[0233] In practical applications, for positioning applications that do not require a wide ranging range, the corresponding subcarrier group spacing can be increased, which reduces the amount of feedback data and reduces feedback overhead and power consumption.

[0234] In a specific implementation process, the number of subcarriers included in the subcarrier group may alternatively be related to the feedback capability of the first node, for example, the amount of data that can be fed back. For example, a smaller amount of data that can be fed back by the first node indicates a larger amount of subcarrier data included in the subcarrier group. Or, a larger amount of data that can be fed back by the first node indicates a smaller amount of subcarrier data included in the subcarrier group.

[0235] In an optional implementation form, a reference power level (RPL) may be used as a reference value, and channel state information to be fed back, such as an IQ value, is expressed as a relative value to the RPL.

[0236] for example,

number

[0237] In a specific implementation, for one or more carrier channels, only one reference value RPL [dBm] may be fed back to reduce the amount of data for feeding back CSI information. Alternatively, one reference value is fed back for each of C carrier channels, where C is a positive integer. Alternatively, one reference value is fed back for each of S subcarriers, where S is a positive integer. Optionally, for a carrier channel, the reference value RPL [dBm] needs to be fed back together with the CSI information (e.g., the CSI information shown in Table 2 or Table 3). The reference value RPL is set to help increase the dynamic range of the CSI feedback information, so that limited information bits can indicate more CSI, improve the accuracy of measurement information feedback, and reduce quantization errors.

[0238] When the frequency hopping frequency bandwidth range is large, different RPL values ​​may be fed back on different channels. For example, RPL1 is fed back on channel 1 and RPL2 is fed back on channel 2. The different RPL values ​​are set based on the average power of received symbols on different channels. This can overcome frequency selectivity when the frequency hopping frequency bandwidth range is large and provide more accurate CSI quantification values.

[0239] Examples of the amount of data fed back are as follows: For one 80 MHz OFDM signal measurement, the amount of data fed back is 38*4*12*2=3648 bits; or, for three 80 MHz OFDM signal measurements, the amount of data fed back is 38*4*12*2*3=10944 bits. It can be seen that even with 80 MHz OFDM frequency hopping, the amount of data fed back does not exceed 11 kbits. The above scheme can effectively reduce the amount of data feedback, so that the first node can complete the transmission of CSI feedback information in a short time.

[0240] The above steps S201 to S203 provide a solution for how the first node feedbacks measurement information when the first node and the second node perform ranging interaction. Specifically, after obtaining first measurement information by measuring a first ranging frame, the first node transmits second measurement information to the second node based on the first measurement information and a first feedback scheme. This can improve the reliability of ranging. In addition, the above solution provides multiple feedback schemes. The first node may flexibly select any feedback scheme for feedback. Compared with a single fixed feedback scheme, this feedback scheme can implement flexible feedback of measurement information.

[0241] It can be understood that in this embodiment of the present application, when the first node is a T node, the CSI information of the first node is fed back in two feedback types, where feedback type 1 is the CSI information measured for the G node, and feedback type 2 is the CSI information measured for the T node. The aforementioned two types of CSI feedback procedures are described as follows:

[0242] Feedback Type 1: In SLB, since the initial carrier channel only supports G link symbols and T link symbols carrying CSI feedback information, T nodes participating in frequency hopping ranging need to feedback CSI information to the G node. If the measurement node or positioning node is a G node, the G node performs a combination process on the CSI information based on the CSI information of at least one T node measured by the G node and the CSI information received from at least one T node to obtain a ranging result. The ranging result includes the distance between the first node and the second node.

[0243] Feedback Type 2: In SLB, when the G node and the T2 node are positioning anchors and the T1 node is the measurement target node (measurement node), the T1 node first transmits the measured CSI information of the T2 node (represented as T2-T1) to the G node, and then the G node transmits the received CSI information T2-T1 to the T2 node, so that the T2 node can perform combination processing on the measured CSI information of the T1 node (T1-T2) and the CSI information received from the G node (T2-T1) to obtain the distance between the T1 node and the T2 node.

[0244] This helps to reduce the time interval between ranging interactions on different channels, shortens the total duration of channel frequency hopping measurements, helps to deal with dynamic channel changes during ranging of moving targets, and improves ranging accuracy.

[0245] In a possible design, after step S203, the second node may obtain a ranging result based on the second measurement information, where the ranging result includes a distance between the first node and the second node.

[0246] For example, the ranging interaction between the first node and the second node is a bilateral ranging interaction. Specifically, the first node measures a ranging frame (i.e., a first ranging frame) transmitted by the second node, and the second node also measures a ranging frame (e.g., a second ranging frame) transmitted by the first node. Correspondingly, the second node receives the second ranging frame on at least one channel and measures the second ranging frame to obtain third measurement information. The second node determines a ranging result based on the second measurement information and the third measurement information. The ranging result includes the distance between the first node and the second node.

[0247] In a possible design, the first node and the second node may perform frequency hopping ranging.

[0248] For example, at least one channel belongs to a first channel group, and before step S201 or after step S203, the method includes:

[0249] The method may further include the second node transmitting a third ranging frame on the second channel group, the first node receiving the third ranging frame on the second channel group, the first node measuring the third ranging frame to obtain fourth measurement information, and the first node transmitting fifth measurement information based on the fourth measurement information and the first feedback scheme. The second channel group includes one or more channels, and the second channel group has at least one channel different from the first channel group.

[0250] For example, Figure 11 shows an example of frequency hopping ranging. The first node and the second node may separately perform ranging interactions for channel groups 1, 2, and 3. S201 to S203 may be ranging interactions for any one of channel groups 1, 2, and 3.

[0251] Frequency hopping ranging implements the technical effect of combined wideband signal measurement, which can improve ranging resolution and ranging accuracy.

[0252] In a possible design, after measuring the first ranging frame, in addition to feeding back CSI information (i.e., transmitting second measurement information) and RPL, the first node may also feed back the SNR of at least one channel. The SNR may be the SNR corresponding to one or more carrier channels, or may be the average SNR corresponding to one carrier channel group. This is not limited in this application. The unit of SNR is dB.

[0253] In this way, the second node may perform ranging calculations on the CSI information based on the signal quality of the CSI information, for example, by combining the CSI information of a channel with a high SNR, thereby improving ranging accuracy. In addition, if the SNR is insufficient to indicate the signal quality, the signal quality of the CSI information may be indicated in the form of signal quality evaluation or scoring.

[0254] In a possible design, the first node may feedback measurement information (e.g., the second measurement information and the fifth measurement information) on at least one initial carrier channel. For example, as shown in FIG. 11 , the initial carrier channel of the first node and the second node is channel group 3. After completing three ranging interactions, the first node and the second node return to channel group 3 to perform centralized feedback of channel state information.

[0255] It may be understood that the implementations herein may be implemented separately or in combination with each other.

[0256] Based on the same technical concept, one embodiment of the present application provides a ranging device, which includes a module, unit, or means configured to implement the method implemented by the first node or the second node in the above-mentioned method embodiments. The module, unit, or means may be implemented by software, hardware, or hardware executing corresponding software.

[0257] For example, referring to FIG. 12, the apparatus may include a receiving module 1201, a processing module 1202, and a transmitting module 1203.

[0258] When the device is located at a first node, the receiving module 1201 is configured to receive a first ranging frame on at least one channel. The processing module 1202 is configured to measure the first ranging frame to obtain first measurement information. The transmitting module 1203 is configured to transmit second measurement information based on the first measurement information and a first feedback scheme.

[0259] When the device is located at a first node, the transmitting module 1203 is configured to transmit a first ranging frame on at least one channel, where the first ranging frame is used by the first node to perform measurements to obtain first measurement information, and the receiving module 1201 is configured to receive second measurement information from the first node, where the second measurement information is determined based on the first measurement information and a first feedback scheme.

[0260] It should be understood that all relevant contents of the steps in the foregoing method embodiments may be cited in the functional descriptions of the corresponding functional modules, and the details will not be described again in this specification.

[0261] In a specific implementation, the device may have multiple product forms, some possible ways are described below.

[0262] See Figure 13. An embodiment of the present application further provides a ranging device. The device includes at least one processor 1301 and an interface circuit 1302. The interface circuit 1302 is configured to receive a signal from a device other than the device and send the signal to the processor 1301, or receive a signal from the processor 1301 and send the signal to a communication device other than the device. The processor 1301 is also configured to implement a method performed by the first device or the second device via a logic circuit or by executing code instructions.

[0263] It should be understood that the processor referred to in this embodiment of the present application may be implemented by hardware or software. When the processor is implemented by hardware, the processor may be a logic circuit, an integrated circuit, etc. When the processor is implemented by software, the processor may be a general-purpose processor and is implemented by reading software code stored in a memory.

[0264] For example, a processor may be a Central Processing Unit (CPU), or may be another general-purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or another programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc. A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, etc.

[0265] It should be understood that the memory referred to in the embodiments of this application may be volatile or nonvolatile memory, or may include both volatile and nonvolatile memory. Nonvolatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory may be random access memory (RAM) used as an external cache. By way of example and not limitation, many forms of RAM may be available, such as static random access memory (Static RAM, SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (Synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (Double Data Rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (Enhanced SDRAM, ESDRAM), Synchlink dynamic random access memory (Synchlink DRAM, SLDRAM), and direct Rambus random access memory (Direct Rambus RAM, DR RAM).

[0266] It should be noted that if the processor is a general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, the memory (storage module) may be integrated into the processor.

[0267] It should be noted that memory as described herein is intended to include, without being limited to, these and other suitable types of memory.

[0268] Based on the same technical concept, an embodiment of the present application further provides a computer-readable storage medium containing a program or instruction, which, when run on a computer, performs a method implemented by a first node or a second node.

[0269] Based on the same technical concept, an embodiment of the present application further provides a computer program product including instructions, the computer program product storing the instructions, which, when run on a computer, cause a method to be performed by a first node or a second node.

[0270] Based on the same technical concept, an embodiment of the present application further provides a ranging system including the first node or the second node.

[0271] Based on the same technical concept, an embodiment of the present application further provides a terminal device which is the first node or the second node described above, or is located on the first node or the second node described above. The terminal device may be a vehicle, an unmanned aerial vehicle, a helicopter, an airplane, a ship, an intelligent transportation device, a smart home device, etc. The specific form of the terminal device is not limited in the embodiments of the present application.

[0272] In this application, "at least one" means one or more, and "multiple" means two or more. "And / or" describes a relationship between related objects and indicates that three relationships may exist. For example, A and / or B refers to three cases: when only A is present, when both A and B are present, and when only B is present, where A and B may each be singular or plural. In text descriptions in this application, the character " / " represents an "or" relationship between related objects. In formulas in this application, the character " / " represents a "divide by" relationship between related objects. "Comprising at least one of A, B, and C" may represent including A, including B, including C, including A and B, including A and C, including B and C, and including A, B, and C.

[0273] Those skilled in the art will understand that the embodiments of the present application may be provided as a method, a system, or a computer program product. Thus, the present application may take the form of a hardware-only embodiment, a software-only embodiment, or an embodiment having a combination of software and hardware. In addition, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk memory, CD-ROM, and optical memory) containing computer-usable program code.

[0274] The present application has been described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the present application. It will be understood that computer program instructions can be used to implement each procedure and / or each block in the flowcharts and / or block diagrams, and combinations of procedures and / or blocks in the flowcharts and / or block diagrams. These computer program instructions may be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or any other programmable data processing device to generate a machine, whereby the instructions, executed by the processor of the computer or any other programmable data processing device, generate an apparatus for implementing the specific function(s) in one or more procedures in the flowcharts and / or one or more blocks in the block diagrams.

[0275] These computer program instructions may be stored in a computer-readable memory that can cause a computer or some other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable memory produce an artifact that includes an instruction apparatus that implements a particular function or functions of one or more procedures in the flowcharts and / or one or more blocks in the block diagrams. [Explanation of symbols]

[0276] 0~12 Radio frame structure 1201 Receiver Module 1202 Processing Module 1203 Transmitting Module 1301 processor 1302 Interface circuit

Claims

1. receiving, by a first node, a first ranging frame on at least one channel and measuring, by the first node, the first ranging frame to obtain first measurement information; transmitting second measurement information by the first node based on the first measurement information and a first feedback scheme; A ranging method including:

2. the first ranging frame includes at least one symbol; The method of claim 1 , wherein the first measurement information indicates channel state information of at least one valid subcarrier corresponding to the at least one symbol.

3. The method of claim 2 , wherein the first feedback scheme refers to feedback of channel state information of all valid subcarriers, and the second measurement information and the first measurement information refer to the same channel state information.

4. 3. The method of claim 2, wherein the first feedback scheme indicates feedback of channel state information of a direct current (DC) subcarrier, the second measurement information includes channel state information of a DC subcarrier corresponding to the at least one symbol, and the channel state information of the DC subcarrier is determined by performing interpolation based on channel state information of valid subcarriers adjacent to the DC subcarrier.

5. The method of claim 4 , wherein the interpolation comprises at least one of linear interpolation, nearest neighbor interpolation, cubic spline interpolation, and / or quadratic interpolation.

6. 3. The method of claim 2, wherein the first feedback scheme indicates feedback of channel state information of at least one subcarrier group, the at least one valid subcarrier corresponding to the at least one symbol belongs to the at least one subcarrier group, and the second measurement information includes channel state information of each subcarrier group in the at least one subcarrier group.

7. there is one subcarrier group for every M consecutive subcarriers corresponding to said at least one symbol, where M is a positive integer; or 7. The method of claim 6, wherein there is one subcarrier group for every P or L consecutive subcarriers corresponding to the at least one symbol, where P and L are positive integers and P≠L.

8. the at least one channel includes a first channel and a second channel; 7. The method of claim 6, wherein there is one subcarrier group for every Q consecutive subcarriers in the subcarriers corresponding to the first channel, and there is one subcarrier group for every N consecutive subcarriers in the subcarriers corresponding to the second channel, where Q and N are positive integers and Q≠N.

9. 9. The method of claim 6, wherein the channel state information for each subcarrier group is the average, median, maximum, or minimum value of the channel state information of all valid subcarriers in the subcarrier group, or the channel state information of one subcarrier in the subcarrier group.

10. The method according to any one of claims 6 to 9, wherein the number of subcarriers included in a subcarrier group is related to the ranging range.

11. a symbol in the first ranging frame has a cyclic prefix CP, and measuring the first ranging frame by the first node includes performing measurements by the first node starting from a first symbol in the first ranging frame; or a symbol in the first ranging frame does not have a CP, and measuring the first ranging frame by the first node comprises performing measurements by the first node starting from a second symbol in the first ranging frame; or 11. The method of claim 1, comprising: performing measurements by the first node based on instruction information or preset settings, starting from a specified symbol in the first ranging frame.

12. the first ranging frame includes a plurality of symbols, and the step of measuring the first ranging frame by the first node comprises: determining, by the first node, channel state information corresponding to an Rth symbol in the first ranging frame based on channel state information corresponding to the plurality of symbols, where R is a positive integer and the first measurement information indicates the channel state information corresponding to the Rth symbol; or determining, by the first node based on channel state information corresponding to the plurality of symbols, an average value of the channel state information corresponding to the plurality of symbols, wherein the first measurement information indicates the average value of the channel state information corresponding to the plurality of symbols.

12. The method of any one of claims 1 to 11, comprising:

13. the symbols in the first ranging frame use overhead symbol resources in a first type radio frame, the first type radio frame including data symbols and the overhead symbols, and the at least one channel is an initial carrier channel; or the symbols in the first ranging frame use resources of both data symbols and overhead symbols in a first type radio frame, the first type radio frame including the data symbols and the overhead symbols, and the at least one channel is an initial carrier channel; or 13. The method of claim 1, wherein the symbols in the first ranging frame use data symbols in a second type radio frame, and all symbols in the second type radio frame are data symbols, and the at least one channel is an initial carrier channel or a channel after frequency hopping.

14. The following information is obtained by said first node: a first indication indicating a type of the first ranging frame; second indication information indicating that the first ranging frame has the CP or does not have the CP; third indication information indicating that the first ranging frame has a normal CP or an extended CP; fourth indication information indicating that the first node feeds back channel state information of the at least one channel and / or channel number information of the at least one channel; fifth instruction information indicating a measurement start position within the first ranging frame; sixth indication information, indicating that the first node feeds back the channel state information corresponding to the Rth symbol in the first ranging frame, where R is a positive integer; seventh indication indicating that the first node feeds back the average value of the channel state information corresponding to the plurality of symbols in the first ranging frame; and eighth indication information indicating the first feedback manner in which the first node feeds back channel state information, the first feedback manner being feeding back the channel state information of the at least one subcarrier group, feeding back the channel state information of the DC subcarrier, or feeding back the channel state information of all the enabled subcarriers.

14. The method of claim 1, further comprising transmitting or receiving one or more types of:

15. When the first feedback scheme is feeding back the channel state information of the at least one subcarrier group, the first node may receive the following information: a ninth indication indicating a grouping parameter of the at least one subcarrier group; and tenth instruction information indicating how to calculate the channel state information of the at least one subcarrier group; 15. The method of claim 14, further transmitting or receiving one or more of:

16. The method comprises: calibrating the first measurement information based on calibration information to obtain calibrated first measurement information, the calibration information being determined based on the at least one channel; the step of transmitting, by the first node, second measurement information based on the first measurement information and a first feedback scheme, transmitting, by the first node, the second measurement information based on the calibrated first measurement information and the first feedback scheme.

16. The method of any one of claims 1 to 15, further comprising:

17. The method comprises:

17. The method of claim 1, further comprising transmitting, by the first node, a second ranging frame on the at least one channel, wherein the second ranging frame is used by the second node to perform measurements to obtain third measurement information.

18. the at least one channel belongs to a first channel group, and the method further comprises: receiving, by the first node, a third ranging frame on a second channel group and measuring, by the first node, the third ranging frame to obtain fourth measurement information, the second channel group including one or more channels, the second channel group having at least one channel different from the first channel group; transmitting, by the first node, fifth measurement information based on the fourth measurement information and the first feedback scheme; 18. The method of any one of claims 1 to 17, further comprising:

19. The method comprises:

20. The method of claim 18, comprising transmitting, by the first node, the second measurement information and the fifth measurement information on at least one primary carrier channel.

20. The method of claim 12 , wherein the value of R is preset or predefined.

21. the channel state information includes a relative value of a relative reference power level RPL; The method comprises: transmitting, by the first node, the RPL; 21. The method of any one of claims 1 to 20, further comprising:

22. transmitting, by said first node, a signal-to-noise ratio SNR of said at least one channel.

22. The method of any one of claims 1 to 21, further comprising:

23. transmitting, by a second node on at least one channel, a first ranging frame for ranging; receiving, by the second node, second measurement information from the first node, the second measurement information corresponding to the first ranging frame and a first feedback scheme, the second measurement information being used to determine a ranging result, the ranging result including a distance between the first node and the second node; A ranging method including:

24. The method comprises: receiving, by the second node, a second ranging frame on the at least one channel and measuring the second ranging frame to obtain third measurement information; determining, by the second node, the ranging result based on the second measurement information and the third measurement information; 24. The method of claim 23, further comprising:

25. the at least one channel belongs to a first channel group, and the method further comprises: transmitting a third ranging frame for ranging by the second node on a second channel group, the second channel group including one or more channels, the second channel group having at least one channel different from the first channel group; receiving, by the second node, fifth measurement information from the first node, the fifth measurement information corresponding to the third ranging frame and the first feedback scheme; 25. The method of claim 23 or 24, further comprising:

26. The method comprises:

26. The method of claim 25, comprising receiving, by the second node, the second measurement information and the fifth measurement information on at least one primary carrier channel.

27. The method comprises: receiving, by the second node, the SNR of the at least one channel; 27. The method of any one of claims 23 to 26, further comprising:

28. a receiving module configured to receive a first ranging frame on at least one channel; a processing module configured to measure the first ranging frame to obtain first measurement information; a transmitting module configured to transmit second measurement information based on the first measurement information and a first feedback scheme; A distance measuring device comprising:

29. A distance measuring device, a transmitting module configured to transmit a first ranging frame for ranging on at least one channel; a receiving module configured to receive second measurement information from the first node, the second measurement information corresponding to the first measurement information and a first feedback scheme, the second measurement information being used to determine a ranging result, the ranging result including a distance between the first node and a node where the ranging device is located; and A distance measuring device comprising:

30. 1. A ranging device comprising at least one processor and an interface circuit, A ranging device, wherein the interface circuit is configured to receive signals from a device other than the device and transmit the signals to the processor, or receive signals from the processor and transmit the signals to a device other than the device, and wherein the processor is configured to implement the method of any one of claims 1 to 22 or the method of any one of claims 23 to 27 via logic circuits or by executing code instructions.

31. 28. A computer-readable storage medium having stored thereon a computer program or instructions that, when executed by a communication device, implements the method of any one of claims 1 to 22 or the method of any one of claims 23 to 27.

32. 28. A computer program product storing instructions that, when run on a computer, enable the computer to perform the method of any one of claims 1 to 22 or to perform the method of any one of claims 23 to 27.

33. a first node configured to perform the method of any one of claims 1 to 22; a second node configured to perform the method of any one of claims 23 to 27; A ranging system comprising:

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